Record details

    Ocean floor basalt, not continental gabbro: a reinterpretation of the Hoher Bogen amphibolites, Teplá-Barrandian, Bohemian massif
Statement of responsibility
    G. Propach, T. Pfeiffer
    Pfeiffer, T.
    Propach, G.
Source title - serial
    Geologische Rundschau
    Vol. 87, no. 3
    p. 303-313
    6 obr., 1 fot., 3 tab., 2 s.bibl.
    Zkr. název ser.: Geol. Rdsch.
Subject group
    bazalt typu MORB
    chemismus hornin
    kůra oceánská
    mariánskolázeňský bazický komplex
    vrásnění variské
Geographical name
Abstract (in english)
   At its southern margin along the hoher Bogen mountain, the Teplá-Barrandian (Bohemian massif, Central Europe) is made up of a 1- to 4-km wide belt of amphibolites. An upper amphibolites/lower granulite facies Variscan metamorphism has brought forth coarse-grained, weakly foliated rocks with hbl+pl+cpx+opx+grt parageneses. Since the begining of this century, these rocks, together with fine-grained or mylonitized amphibolites, have been regarded as metamorphic gabbros (gabbro amphibolites) of the Neukirchen-Kdyne igneous complex. Relics of magmatic textures, however, cannot be found anywhere. The amphibolites are therefore reinterpreted as metamorphic basalt. The Hoher Bogen amphibolites (HBA) derive from N-type MORB. The most primitive samples have Mg=s between 60 and 65. Locally occurring (garnet-) hornblendites and leucodiorites mobilisates are the products of partial melting of amphibolites during the Variscan metamorphism and do not belong to the primary magmatic rock association.
   Ultramafic rocks are tectonically emplaced between the HBA belt and the metampelitic rocks of the Moldanubian. At the very least, the metapyroxenites among them seem to have a cumulus origin. Together with the ultramafic rocks, the HBA belt may be regarded as a metaophiolite, comparable to the Mariánské Lázně complex. The reinterpretation of the the former "gabbro amphibolites" as a metaophiolite has consequences for the geology of the Teplá-Barrandian: the size of the Neukirchen-Kdyne igneous complex is reduced. The HBA belt is a piece of oceanic crust which is possibly younger than the Precambrian metasedimentary/metavolcanic country rock of the Neukirchen-Kdyne igneous complex
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
Entered date
    3. 1. 2008
Import date
    8. 8. 2012